As the demand for fuels such as aviation and diesel fuels increase worldwide, there is increasing interest in sources other than petroleum crude oil for producing the fuel. One source is renewable feedstocks including, but not limited to, plant oils such as corn, jatropha, camelina, rapeseed, canola, soybean and algal oils, animal fats such as tallow, fish oils, and various waste streams such as yellow and brown greases. The common feature of these feedstocks is that they are composed of mono- di- and tri-glycerides, and free fatty acids (FAA). Another class of compounds appropriate for these processes is fatty acid alkyl esters (FAAE), such as fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE). These types of compounds contain aliphatic carbon chains generally having from about 8 to about 24 carbon atoms. The aliphatic carbon chains in the glycerides, FFAs, or FAAEs can be saturated or mono-, di- or poly-unsaturated. Most of the glycerides in the renewable feed stocks will be triglycerides, but some may be monoglycerides or diglycerides. The monoglycerides and diglycerides can be processed along with the triglycerides.
There are reports disclosing the production of hydrocarbons from renewable feedstocks. For example, U.S. Pat. No. 4,300,009 discloses the use of crystalline aluminosilicate zeolites to convert plant oils (e.g., corn oil) to hydrocarbons (e.g., gasoline), and chemicals (e.g., para-xylene). U.S. Pat. No. 4,992,605 discloses the production of hydrocarbon products in the diesel boiling range by hydroprocessing vegetable oils such as canola or sunflower oil. Finally, US 2004/0230085 A1 discloses a process for treating a hydrocarbon component of biological origin by hydrodeoxygenation followed by isomerization.